Electric heating device.



* H. W.. ELBGTMG HEATING DEVICE.

APPLICATION FILED 0CT.31,1911.

Patented JunevSO, 191%.

UNITED STATES PATENT OFFICE.

HARRY W. DENHARD, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR T THE CUTLEE- HAMMER MFG. C0., OF MILWAUKEE, WISCONSIN, .A CORIRATION OF WISCONSIN.

ELECTRIC HEATING DEVICE.

Specication of Letters Patent.

' Patented J une 30, 1914.

Application filed October 31, 1911. Serial No. 657,811.

a citizen of the United States, residing at San Francisco, vin the county of San Francisco and State of California, have invented new and useful Improvements in Electric Heating Devices, of which the following is a full, clear, concise, andeXact description,

yreference being had to the accompanying drawing, forming a part of this specification.

My invention relates to electric heating devices.

It has among its objects to provide an improved electric heating device.-

A further object of my invention is to provide an improved electric heating device wherein the supply of ycurrent through the device is automatically controlled by the object to be heated.

A further object of my invention is to provide an improved electric heating device of this type which is especially adapted to use as an electric tool or curling iron heater, an automatic switch device bein employed to cut the heater in or out of circuit when the tool or other device is inserted in the heater.

Other objects and advantages of my improved construction' will hereinafter appear.

In the accompanyingdrawings I have for purposes of illustration shown one form which my invention may assume in practice. My invention is not, however, limited to this form, but may assume other forms.

In the views of these drawings: Figure 1 shows a central sectional view through the device. Fig. 2 shows an end elevation of the devicel Fig. 3 shows a diagrammatic view of the circuit connections.

In the construction shown in the drawings for purposes of illustration, I have illustrated a casing 1 mounted upon a base 2 and having a central chamber 3 arranged to receive the object to be heated l1; a resistance material 5 being wound around the heating chamber, and the current supply to this lre sistance material being controlled by a snap switch mechanism 7 actuated by the movement of a door 8 of the chamber 3.

held in central position within the casing by means of end members 10 and 11, which are attached by means ,of suitable screws 12 and 13 to the outer casing 1. In a preferred form the end members 10 and 11 preferably project into the ends of the sleeve 9, the end member 10 closing this end of the sleeve, while the end member 11 is provided with a flange which encircles the mouth of the sleeve. In a preferred form the casing 1 is spaced from the sleeve 9 a suitable distance and is so constructed as to form a sealed heat retaining chamber 14; surrounding the sleeve 9. In a preferred form a bottom strip 15 is arranged beneath the under side of the casing 1. This bottom strip 15 is preferably so arm-fed as to extend at an angle of substantially 30 degrees with respect to the base member 2, so

that the article to be heated may be more readily inserted, andis supported in this position by means of a depending supporting plate 16. Further, by this arrangement the heating effect is better. If desired, the bottom plate 15 may be attached to the end plate 10 by a suitable plate 17 in order to provide a more sturdy structure, and the lower end of the end plate 11 may be bent inward and attached to the upper end of the plate l5.. Ina preferred form the plates 15 and 16 are made up in one piece of stamped metal. v

Around the sleeve 9 the resistance mate rial 5 is preferably wound. This resistance material may be of any desired type. For purposes ofillustration I have shown the same' to consist of a single length of helically coiled resistance wire wound upon an insulating sheet 18 inclosing the sleeve 9. In a preferred form the resistance material is so wound around the sleeve 9 that it does not Contact with any of the metal parts of the casing at either end of the latter. It is to be noted that this resistance material is housed in the sealed heat retaining chamber 14, so that the heat developed by the same is. not readily transmitted to the outside of the casing so that it may be dissipated in the atmosphere.

The door mechanism is preferably located at one end ofthe chamber 3 and in a preferred form is adapted to close the opening in the end member 11, and is preferably provided with a rounded outer surface 20 adapted-to-be engaged bythe articles or objects to be. inserted in the heating chamber. The'lowerv end of the'door 8 is preferably provided with extensions 22 swiveled on a rod 2l journaled as.' at 23 in the opposite sides of the casing. In a preferred form the rod 21 is varranged beneath the chamber 3 and the lower end of the door extends I through 'a suitable opening 24 in the sleeve 9. `A link 25 is preferably arranged to move withv the depending end of the door when the door is moved'. aboutits pivot, and is `preferably connected through any suitable lconnecting means to the snap'. .witch mecliamaybe made through a secondinsulating nism 7, preferably carried onAV the base beneath the'casing. If desired, this connection l link 26 anda wire 27 extending through an yao- .preferred form I employ a switch mechanism of the type described in the patent of Charles J. Klein, No. 985,421,.iled Sept. 6,1907, wherein a reciprocating cam member' 32 in' the form of double frustum, positioned base to base, is reciprocated to cause a garter spring 33, through which the cam. Y member moves, to throw a movable contact0r34 to .the opposite limits of its travel to make or break the circuit at contacts with a quick snap action. In a preferred form the switch mechanism is inclosed in a casing 36 between insulating bases 37,"and the cammember 32 is provided with the spindle 38, which extends through asuitable opening in the plate 30 toward the back of the'casing, where it passes through a suit-- able opening in a depending plate 39. In a .preferred form the free endY of the spindle 38 is surroundedby a helical spring 40 and carriesV on oneof its ends a iixed collar 4l,

which is .attached to the wire 27 by any .suitable means. If desired, a guiding stud 42 carried on the frame 1 may. be used to guide the wire 27 in its movement.

In Fig. 3 I have illustrated a diagram of one form of circuit connections for the heater-,the mechanical parts of the device being only roughly indicated and referred to by the same reference numerals as in the previous description. The heating coil 5 for the heater is, as therein shown, preferably arranged in ...Series with the line, and the contacter 3.4v is arranged to'make or break.

the circuit `*of this heating coil at the contacts 35. when the door 8-is actuated. Thus it is seenthat when the object to'be heated is .inserted in the heating chamber the door 8 is actuated to` swing it to the left about its pivot, 27 upwar drawing the collar 4l to the right. 'The movement of this collar 41 against the spring l0 carries with it the spindle 38 and the cam member 32. When the cam member 3.2 passesthrough the garter spring 33 the contactor 34 is thrown to the opposite limit of its travel beyond the opposite slope ofthe cam with a very quick snap action and makes the circuit of the device at the contacts 35. the object to be heated is withdrawn from the heating chamber the circuitof the heating coil 5 is broken, so that the control of the heat supply to the heating chamber is automatic, and no current is flowing in the device except when an object to be heated is within the same.

By my improved construction I have provided an exceedingly simple heating device, in whichthe current supply is automatically controlled by the insertion or removal -of the device to be heated. The heating unit i 1s further inclosed in a chamber which serves to conserve and concentrate the heataboutI the heating chamber and prevent the loss of heat by radiation. Further, the parts are eifectually insulated so that there is no danger of short circuiting. The operation of the snap switch mechanism is such as to make or break the circuit very quickly. Further` the construction is a very rugged one, in which the parts are amply protected and are so arranged as to withstand long use and service. Further, the device may be made up in such a light form that it may be readily carried about, and'presents a very neat and pleasing appearance.

lVhile Ihave in this application described one specific form which my invention may assume in practice, I do not wish to be lim- -ited to this form chosen for purposes -of illustration, but wish rather to include within the scope vof this application all of those forms of' my invention falling within its spirit.-

. lVhat I claim as new and desire to secure by Letters Patent is l. In an electric heating device, a heating coil, and means actuated by an object toV be heated and independent of the rate of movement thereof for changing the circuit connections of said coil with a quick snap action. l

2. In an electric heating device, a casing having a chamber therein, a heating coil for said chamber, means for closing said chamber, and means rendered operative by an object to be heated but actuated independently thereof for changing the circuit connections for said coil with a quick snap action.

3. In an electric heating device, a frame, a hollow heating coil mounted therein, means normally closing an opening in one end of said coil, and a snap switch mecha- Conversely, whenv :ne result of pulling the wire nism operated upon movement of said clos-v mg means to change the circuit connect-ions of said coil with a uick snap action.`

4. In an' electric eating device, a frame, a sleeve member supported between the end members of said frame, a heating coil wound around said sleeve and yinsulated therefrom, saidheating coil being inclosed in a sealed cha1nber,.means normally closing one end of said sleeve and means actuated upon movement of an object to be 4heated for making or breaking the circuit connections of said coil with a quick snap action.

5. In an electric heating device, a frame, a heating coil carried thereby, a sleeve inclosed within said coil and insulated therefrom, a door normally closing one end of saidsleeve a snap switch mechanism carried by said members connecting said door and switch frame. and means including link mechanism for changing the circuit connections of said coil with a quick snap action upon movement of said door.

46. Inv an' electric heating device, a metallic casing, a heating coil carried therein, a metal sleeve inclosed in said coil and vinsulated therefrom, one end of said sleeveA being closed by saidcasing, and said coil being inclosed in a sealed chamber,`a door normally closing the other end of said sleeve, a snap switch mechanism carried by said casing beneath said coil, and means including a flexible connection for actuating saidswitch mechanism wit-h a-quick snap action when said door is moved.

7.1111 an electric heating device, a substantially horizontal base, aY frame carried thereon and disposed atan angle with respectatliereto, saidframe having aehamber formedtherein, a heating coil surrounding said chamber, a door closing one end of said chamber, a vsnap switch mechanism housedv l between said frame and said base, and operative connections between said door and said snap switch mechanism for changing the circuit connections of said coil with a quick snap action when an object to be heated is inserted in orl removed from said chamber.

In witness whereof, I have hereunto sub- 'scribed my name in the presence of two 

